My roommate was complaining about how his Sport with blue band was not vibrating when receiving notifications more 8/10 times. He talked to Apple support and booked a GB appointment for 1pm and just left with a new replacement watch. The watch now properly vibrates, although he thinks it's a very light vibration, on every notification. Just for those who are wondering about doing the same. Contact support first to see if they have replacement stock. This was done at Natick Mall in Natick, Mass. I'm still waiting for my 38mm Space Grey Sport 3:04am still processing.